Class: RbbtProcessQueue::RbbtProcessQueueWorker

Inherits:
Object
  • Object
show all
Defined in:
lib/rbbt/util/concurrency/processes/worker.rb

Defined Under Namespace

Classes: Respawn

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(queue, callback_queue = nil, cleanup = nil, respawn = false, &block) ⇒ RbbtProcessQueueWorker

Returns a new instance of RbbtProcessQueueWorker.



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 113

def initialize(queue, callback_queue = nil, cleanup = nil, respawn = false, &block)
  @queue, @callback_queue, @cleanup, @block = queue, callback_queue, cleanup, block

  @pid = Process.fork do
    Misc.pre_fork

    @cleanup.call if @cleanup
    @queue.close_write 

    if @callback_queue
      Misc.purge_pipes(@callback_queue.swrite) 
      @callback_queue.close_read 
    else
      Misc.purge_pipes
    end

    if respawn
      run_with_respawn respawn
    else
      run
    end
  end
end

Instance Attribute Details

#block ⇒ Object (readonly)

Returns the value of attribute block.



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 4

def block
  @block
end

#callback_queue ⇒ Object (readonly)

Returns the value of attribute callback_queue.



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 4

def callback_queue
  @callback_queue
end

#cleanup ⇒ Object (readonly)

Returns the value of attribute cleanup.



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 4

def cleanup
  @cleanup
end

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 4

def pid
  @pid
end

#queue ⇒ Object (readonly)

Returns the value of attribute queue.



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 4

def queue
  @queue
end

Instance Method Details

#abort ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 142

def abort
  begin
    Process.kill :INT, @pid
  rescue
  end
end

#done? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 149

def done?
  begin
    Process.waitpid @pid, Process::WNOHANG
  rescue Errno::ECHILD
    true
  rescue
    false
  end
end

#join ⇒ Object

Raises:



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 137

def join
  Process.waitpid @pid
  raise ProcessFailed unless $?.success?
end

#run ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 8

def run
  begin
    Signal.trap(:INT){ 
      Kernel.exit! -1
    }

    @stop = false
    Signal.trap(:USR1){ 
      @stop = true
    }

    loop do
      p = @queue.pop
      next if p.nil?
      raise p if Exception === p
      raise p.first if Exception === p.first
      res = @block.call *p
      @callback_queue.push res if @callback_queue
      raise Respawn if @stop
    end
    Kernel.exit! 0
  rescue Respawn
    Kernel.exit! 28
  rescue ClosedStream
  rescue Aborted, Interrupt
    Log.info "Worker #{Process.pid} aborted"
  rescue Exception
    Log.exception $!
    @callback_queue.push($!) if @callback_queue
    Kernel.exit! -1
  ensure
    @callback_queue.close_write if @callback_queue 
  end
  Kernel.exit! 0
end

#run_with_respawn(multiplier = nil) ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes/worker.rb', line 44

def run_with_respawn(multiplier = nil)
  multiplier = case multiplier
               when String
                 multiplier.to_s
               when Fixnum
                 multiplier.to_i
               else
                 3
               end

  status = nil
  begin
    @current = Process.fork do
      run
    end
    @asked = false

    initial = Misc.memory_use(Process.pid)
    memory_cap = multiplier * initial
    Log.medium "Worker #{Process.pid} started with #{@current} -- initial: #{initial} - multiplier: #{multiplier} - cap: #{memory_cap}"

    @monitor_thread = Thread.new do
      begin
        while true
          current = Misc.memory_use(@current) 
          if current > memory_cap and not @asked
            Log.medium "Worker #{@current} for #{Process.pid} asked to respawn -- initial: #{initial} - multiplier: #{multiplier} - cap: #{memory_cap} - current: #{current}"
            RbbtSemaphore.synchronize(@callback_queue.write_sem) do
              Process.kill "USR1", @current
            end
            @asked = true
          end
          sleep 3 + rand(5)
        end
      rescue
        Log.exception $!
      end
    end

    while true
      pid, status = Process.waitpid2 @current
      code = status.to_i >> 8 
      break unless code == 28
      @current = Process.fork do
        run
      end
      @asked = false
      Log.high "Worker #{Process.pid} respawning to #{@current}"
    end
  rescue Aborted, Interrupt
    Log.warn "Worker #{Process.pid} aborted"
    Kernel.exit! 0
    Process.kill "INT", @current 
  rescue Exception
    Log.exception $!
    raise $!
  ensure
    @monitor_thread.kill
    Process.kill "INT", @current if Misc.pid_exists? @current
    @callback_queue.close_write if @callback_queue 
  end

  if status
    Kernel.exit! status.to_i >> 8
  else
    Kernel.exit! -1
  end
end